NEW YORK CITY — For more than a year, the Manhattan District Attorney's office and city investigators conducted a pay-to-play probe of elected officials that led to at least one arrest of a contractor who tried to bribe a city councilwoman, DNAinfo.com New York has learned.

The probe — involving a cooperating witness who once held a top job in City Councilman Al Vann's office — has focused on whether officials accepted campaign contributions in exchange for favors, including using their political sway to help private firms obtain lucrative city contracts.

As a result of the probe, investigators busted a Bangladeshi-born contractor who has been a major donor to local politicians for trying to give $5,000 in cash to Brooklyn City Councilwoman Darlene Mealy in exchange for her help in securing a contract with the Department of Housing Preservation and Development.

Mealy, a Democrat who represents Bedford-Stuyvesant, has not been accused of any wrongdoing and denied to DNAinfo any knowledge of the investigation.

The contractor, Mohammed Aziz, pleaded guilty on Dec. 11, 2012, to a misdemeanor charge of criminal facilitation. He got no jail time but agreed to pay a $1,000 fine, according to court records.

Aziz, 55, was caught on a tape recording on Sept. 23, 2011, giving the cooperating witness, identified by sources as Bill Wren, the cash at the corner of South Street and Maiden Lane in lower Manhattan, according to the criminal complaint.

A former deputy chief of staff for Vann who now runs Bedford-Stuyvesant-based nonprofits with HPD contracts, Wren pretended to act as a middleman for Mealy and claimed she would write a letter of support for a contract that Aziz's firm, Delight Construction Corp., was bidding on, according to the complaint and sources.

The Manhattan DA's Office and the city's Department of Investigation declined to comment on the case and wouldn't say whether the probe has concluded and if other arrests were made.

Thomas F. Liotti, Aziz's lawyer, told DNAinfo that his client provided information to the DA's office after getting caught and was instructed to keep quiet about the investigation.

The probe became public when Aziz filed a lawsuit against the New York City Housing Authority on March 13, claiming Delight unfairly lost a $15 million contract with the agency after his bust.

The Bedford-Stuyvesant-based Delight has worked on more than 100 buildings — all through contracts with the city, according Aziz's lawsuit.

While receiving millions of dollars in public funds, Aziz has written many checks to politicians in neighborhoods where he has had projects.

He has personally contributed more than $8,000 to candidates since 2000, including Anthony Weiner, Virginia Fields, Ed Towns and State Sen. Adriano Espaillat.

But his biggest contribution came in 2009, when he gave the maximum $2,750 to Mealy's City Council re-election campaign, city campaign finance records show.

Aziz and others connected with Delight Construction have shelled out at least $12,250 in contributions since 1997, according to city records. The corporation contributed another $7,700 directly to candidates, state records show.

In his lawsuit, Aziz, a Long Island father of two with a heart condition, says that over the course of his career he made many contributions — and that politicians have helped him get work.

"In getting to know elected officials and having access to them, Mr. Aziz was recommended by them for various contracting jobs where he was the lowest responsible bidder and successfully completed those jobs which were awarded him," the lawsuit says.

Aziz claims his English is limited and that he didn't know he was doing anything wrong when he handed the $5,000 to Wren. Despite Aziz's guilty plea, the lawsuit describes the case against him as "borderline entrapment."

Liotti, Aziz's lawyer, said his client simply thought he would get a letter of support to bolster his contract bid.

"Sometimes those letters from public officials, I gather, make a difference on bidding on contracts," Liotti said.

According to an HPD spokesman, it is not uncommon for councilmembers to file letters of recommendation endorsing local developers and projects that might bring affordable housing or jobs to their districts. But he insisted that the letters have little influence on the approval process.

HPD could not immediately locate any letter written by Mealy on Aziz's behalf, but the spokesman said that didn't necessarily mean one was never sent.

One of Aziz's projects for HPD involved Delight partnering with Wren's nonprofit to build low-income housing in Bedford-Stuyvesant in 2007.

Wren and his father, Willie Wren, have operated a series of nonprofits in Brooklyn, including the Dekalb Throop Cluster Housing Development Fund and Miracle Makers of Bed-Stuy Housing Development Fund.

When reached at his Dekalb Throop office on Tuesday, Bill Wren declined to comment on the investigation or the reason he became a cooperating witness. Cooperating witnesses generally work with investigators to secure a more favorable deal in their own criminal cases.

Aside from their former business relationship, Aziz and the Wrens share another thing in common: They like to make donations to local politicians.

Wren and his father are major political donors, with the family and the non-profits they control contributing tens of thousands of dollars to pols, including Vann, City Councilwoman Letitia James, former Mayor Rudy Giuliani, former Govs. David Paterson and Elliot Spitzer, and mayoral candidates Bill Thompson and Public Advocate Bill de Blasio's earlier campaigns.

Willie Wren gave Mealy $1,000 in 2005 and $250 in 2011, city and state records show.

While Bill Wren declined to comment, and his father told DNAinfo that he has never given a contribution with the expectation that a politician would do favors for his nonprofits.

"That's something I don't believe in," Willie Wren said outside his home in Westbury, Long Island. "I'm straight. I'm transparent. If they even ask me, I tell them they are dealing with the wrong guy."

He acknowledged making many campaign donations.

"We always make contributions within reason," he said.

Willie Wren also said that, in his experience as an HPD contractor, a city councilmember's approval can often make or break the deal.

"If they don't sign off on it, then HPD is not going to sign off on it," he said.

The HPD spokesman said that, while councilmembers do weigh in on projects and often contribute discretionary cash to projects, their financial support is not crucial.

He added that the agency always seeks the support of community members, including councilmembers, community board and local residents.

Willie Wren described Mealy as "somewhat of a difficult person to deal with." About four or five years ago, HPD made vacant lots in Bedford-Stuyvesant available for affordable housing, and he went to Mealy for her support, he recalled.

"She said she would get back to us," Wren said. "She never returned our calls."

Mealy vehemently denied any knowledge of the investigation when confronted by DNAinfo in a City Hall elevator this week.

“Don't play that crap with me,” she said. “It’s the first thing I've been hearing.”

She said that she knew Aziz “through a friend” but had never done business with him because he works outside her district. She ignored a question about knowing Bill Wren.

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